am f4535aee: Merge "Update bitmapfun sample to call recycle()" into jb-mr1-dev

# Via Android (Google) Code Review (1) and Chris Banes (1)
* commit 'f4535aee56bf564f962dbcbdc0ce03af98f0ebd4':
  Update bitmapfun sample to call recycle()

samples/training/bitmapfun/res/layout/image_detail_fragment.xml

@@ -25,7 +25,7 @@
         android:layout_height="wrap_content"
         android:layout_gravity="center" />
 
-    <ImageView
+    <com.example.android.bitmapfun.ui.RecyclingImageView
         android:id="@+id/imageView"
         android:layout_width="fill_parent"
         android:layout_height="fill_parent"

samples/training/bitmapfun/src/com/example/android/bitmapfun/ui/ImageDetailFragment.java

@@ -18,7 +18,6 @@ package com.example.android.bitmapfun.ui;
 
 import android.os.Bundle;
 import android.support.v4.app.Fragment;
-import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.View.OnClickListener;

samples/training/bitmapfun/src/com/example/android/bitmapfun/ui/ImageGridFragment.java

@@ -270,7 +270,7 @@ public class ImageGridFragment extends Fragment implements AdapterView.OnItemCli
             // Now handle the main ImageView thumbnails
             ImageView imageView;
             if (convertView == null) { // if it's not recycled, instantiate and initialize
-                imageView = new ImageView(mContext);
+                imageView = new RecyclingImageView(mContext);
                 imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
                 imageView.setLayoutParams(mImageViewLayoutParams);
             } else { // Otherwise re-use the converted view

samples/training/bitmapfun/src/com/example/android/bitmapfun/ui/RecyclingImageView.java

@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.example.android.bitmapfun.ui;
+
+import android.content.Context;
+import android.graphics.drawable.Drawable;
+import android.graphics.drawable.LayerDrawable;
+import android.util.AttributeSet;
+import android.widget.ImageView;
+
+import com.example.android.bitmapfun.util.RecyclingBitmapDrawable;
+
+/**
+ * Sub-class of ImageView which automatically notifies the drawable when it is
+ * being displayed.
+ */
+public class RecyclingImageView extends ImageView {
+
+    public RecyclingImageView(Context context) {
+        super(context);
+    }
+
+    public RecyclingImageView(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    /**
+     * @see android.widget.ImageView#onDetachedFromWindow()
+     */
+    @Override
+    protected void onDetachedFromWindow() {
+        // This has been detached from Window, so clear the drawable
+        setImageDrawable(null);
+
+        super.onDetachedFromWindow();
+    }
+
+    /**
+     * @see android.widget.ImageView#setImageDrawable(android.graphics.drawable.Drawable)
+     */
+    @Override
+    public void setImageDrawable(Drawable drawable) {
+        // Keep hold of previous Drawable
+        final Drawable previousDrawable = getDrawable();
+
+        // Call super to set new Drawable
+        super.setImageDrawable(drawable);
+
+        // Notify new Drawable that it is being displayed
+        notifyDrawable(drawable, true);
+
+        // Notify old Drawable so it is no longer being displayed
+        notifyDrawable(previousDrawable, false);
+    }
+
+    /**
+     * Notifies the drawable that it's displayed state has changed.
+     *
+     * @param drawable
+     * @param isDisplayed
+     */
+    private static void notifyDrawable(Drawable drawable, final boolean isDisplayed) {
+        if (drawable instanceof RecyclingBitmapDrawable) {
+            // The drawable is a CountingBitmapDrawable, so notify it
+            ((RecyclingBitmapDrawable) drawable).setIsDisplayed(isDisplayed);
+        } else if (drawable instanceof LayerDrawable) {
+            // The drawable is a LayerDrawable, so recurse on each layer
+            LayerDrawable layerDrawable = (LayerDrawable) drawable;
+            for (int i = 0, z = layerDrawable.getNumberOfLayers(); i < z; i++) {
+                notifyDrawable(layerDrawable.getDrawable(i), isDisplayed);
+            }
+        }
+    }
+
+}

samples/training/bitmapfun/src/com/example/android/bitmapfun/util/ImageCache.java

@@ -17,10 +17,10 @@
 package com.example.android.bitmapfun.util;
 
 import android.annotation.TargetApi;
-import android.app.ActivityManager;
 import android.content.Context;
 import android.graphics.Bitmap;
 import android.graphics.Bitmap.CompressFormat;
+import android.graphics.drawable.BitmapDrawable;
 import android.graphics.BitmapFactory;
 import android.os.Bundle;
 import android.os.Environment;
@@ -63,7 +63,7 @@ public class ImageCache {
     private static final boolean DEFAULT_INIT_DISK_CACHE_ON_CREATE = false;
 
     private DiskLruCache mDiskLruCache;
-    private LruCache<String, Bitmap> mMemoryCache;
+    private LruCache<String, BitmapDrawable> mMemoryCache;
     private ImageCacheParams mCacheParams;
     private final Object mDiskCacheLock = new Object();
     private boolean mDiskCacheStarting = true;
@@ -126,14 +126,28 @@ public class ImageCache {
             if (BuildConfig.DEBUG) {
                 Log.d(TAG, "Memory cache created (size = " + mCacheParams.memCacheSize + ")");
             }
-            mMemoryCache = new LruCache<String, Bitmap>(mCacheParams.memCacheSize) {
+            mMemoryCache = new LruCache<String, BitmapDrawable>(mCacheParams.memCacheSize) {
+
+                /**
+                 * Notify the removed entry that is no longer being cached
+                 */
+                @Override
+                protected void entryRemoved(boolean evicted, String key,
+                        BitmapDrawable oldValue, BitmapDrawable newValue) {
+                    if (RecyclingBitmapDrawable.class.isInstance(oldValue)) {
+                        // The removed entry is a recycling drawable, so notify it 
+                        // that it has been removed from the memory cache
+                        ((RecyclingBitmapDrawable) oldValue).setIsCached(false);
+                    }
+                }
+
                 /**
                  * Measure item size in kilobytes rather than units which is more practical
                  * for a bitmap cache
                  */
                 @Override
-                protected int sizeOf(String key, Bitmap bitmap) {
+                protected int sizeOf(String key, BitmapDrawable value) {
-                    final int bitmapSize = getBitmapSize(bitmap) / 1024;
+                    final int bitmapSize = getBitmapSize(value) / 1024;
                     return bitmapSize == 0 ? 1 : bitmapSize;
                 }
             };
@@ -184,16 +198,21 @@ public class ImageCache {
     /**
      * Adds a bitmap to both memory and disk cache.
      * @param data Unique identifier for the bitmap to store
-     * @param bitmap The bitmap to store
+     * @param value The bitmap drawable to store
      */
-    public void addBitmapToCache(String data, Bitmap bitmap) {
+    public void addBitmapToCache(String data, BitmapDrawable value) {
-        if (data == null || bitmap == null) {
+        if (data == null || value == null) {
             return;
         }
 
         // Add to memory cache
-        if (mMemoryCache != null && mMemoryCache.get(data) == null) {
+        if (mMemoryCache != null) {
-            mMemoryCache.put(data, bitmap);
+            if (RecyclingBitmapDrawable.class.isInstance(value)) {
+                // The removed entry is a recycling drawable, so notify it 
+                // that it has been added into the memory cache
+                ((RecyclingBitmapDrawable) value).setIsCached(true);
+            }
+            mMemoryCache.put(data, value);
         }
 
         synchronized (mDiskCacheLock) {
@@ -207,7 +226,7 @@ public class ImageCache {
                         final DiskLruCache.Editor editor = mDiskLruCache.edit(key);
                         if (editor != null) {
                             out = editor.newOutputStream(DISK_CACHE_INDEX);
-                            bitmap.compress(
+                            value.getBitmap().compress(
                                     mCacheParams.compressFormat, mCacheParams.compressQuality, out);
                             editor.commit();
                             out.close();
@@ -234,19 +253,20 @@ public class ImageCache {
      * Get from memory cache.
      *
      * @param data Unique identifier for which item to get
-     * @return The bitmap if found in cache, null otherwise
+     * @return The bitmap drawable if found in cache, null otherwise
      */
-    public Bitmap getBitmapFromMemCache(String data) {
+    public BitmapDrawable getBitmapFromMemCache(String data) {
+        BitmapDrawable memValue = null;
+
         if (mMemoryCache != null) {
-            final Bitmap memBitmap = mMemoryCache.get(data);
+            memValue = mMemoryCache.get(data);
-            if (memBitmap != null) {
-                if (BuildConfig.DEBUG) {
-                    Log.d(TAG, "Memory cache hit");
-                }
-                return memBitmap;
-            }
         }
-        return null;
+
+        if (BuildConfig.DEBUG && memValue != null) {
+            Log.d(TAG, "Memory cache hit");
+        }
+
+        return memValue;
     }
 
     /**
@@ -453,12 +473,14 @@ public class ImageCache {
     }
 
     /**
-     * Get the size in bytes of a bitmap.
+     * Get the size in bytes of a bitmap in a BitmapDrawable.
-     * @param bitmap
+     * @param value
      * @return size in bytes
      */
     @TargetApi(12)
-    public static int getBitmapSize(Bitmap bitmap) {
+    public static int getBitmapSize(BitmapDrawable value) {
+        Bitmap bitmap = value.getBitmap();
+
         if (Utils.hasHoneycombMR1()) {
             return bitmap.getByteCount();
         }

samples/training/bitmapfun/src/com/example/android/bitmapfun/util/ImageWorker.java

@@ -76,15 +76,15 @@ public abstract class ImageWorker {
             return;
         }
 
-        Bitmap bitmap = null;
+        BitmapDrawable value = null;
 
         if (mImageCache != null) {
-            bitmap = mImageCache.getBitmapFromMemCache(String.valueOf(data));
+            value = mImageCache.getBitmapFromMemCache(String.valueOf(data));
         }
 
-        if (bitmap != null) {
+        if (value != null) {
             // Bitmap found in memory cache
-            imageView.setImageBitmap(bitmap);
+            imageView.setImageDrawable(value);
         } else if (cancelPotentialWork(data, imageView)) {
             final BitmapWorkerTask task = new BitmapWorkerTask(imageView);
             final AsyncDrawable asyncDrawable =
@@ -222,7 +222,7 @@ public abstract class ImageWorker {
     /**
      * The actual AsyncTask that will asynchronously process the image.
      */
-    private class BitmapWorkerTask extends AsyncTask<Object, Void, Bitmap> {
+    private class BitmapWorkerTask extends AsyncTask<Object, Void, BitmapDrawable> {
         private Object data;
         private final WeakReference<ImageView> imageViewReference;
 
@@ -234,7 +234,7 @@ public abstract class ImageWorker {
          * Background processing.
          */
         @Override
-        protected Bitmap doInBackground(Object... params) {
+        protected BitmapDrawable doInBackground(Object... params) {
             if (BuildConfig.DEBUG) {
                 Log.d(TAG, "doInBackground - starting work");
             }
@@ -242,6 +242,7 @@ public abstract class ImageWorker {
             data = params[0];
             final String dataString = String.valueOf(data);
             Bitmap bitmap = null;
+            BitmapDrawable drawable = null;
 
             // Wait here if work is paused and the task is not cancelled
             synchronized (mPauseWorkLock) {
@@ -274,39 +275,50 @@ public abstract class ImageWorker {
             // bitmap to the cache for future use. Note we don't check if the task was cancelled
             // here, if it was, and the thread is still running, we may as well add the processed
             // bitmap to our cache as it might be used again in the future
-            if (bitmap != null && mImageCache != null) {
+            if (bitmap != null) {
-                mImageCache.addBitmapToCache(dataString, bitmap);
+                if (Utils.hasHoneycomb()) {
+                    // Running on Honeycomb or newer, so wrap in a standard BitmapDrawable
+                    drawable = new BitmapDrawable(mResources, bitmap);
+                } else {
+                    // Running on Gingerbread or older, so wrap in a RecyclingBitmapDrawable
+                    // which will recycle automagically
+                    drawable = new RecyclingBitmapDrawable(mResources, bitmap);
+                }
+
+                if (mImageCache != null) {
+                    mImageCache.addBitmapToCache(dataString, drawable);
+                }
             }
 
             if (BuildConfig.DEBUG) {
                 Log.d(TAG, "doInBackground - finished work");
             }
 
-            return bitmap;
+            return drawable;
         }
 
         /**
          * Once the image is processed, associates it to the imageView
          */
         @Override
-        protected void onPostExecute(Bitmap bitmap) {
+        protected void onPostExecute(BitmapDrawable value) {
             // if cancel was called on this task or the "exit early" flag is set then we're done
             if (isCancelled() || mExitTasksEarly) {
-                bitmap = null;
+                value = null;
             }
 
             final ImageView imageView = getAttachedImageView();
-            if (bitmap != null && imageView != null) {
+            if (value != null && imageView != null) {
                 if (BuildConfig.DEBUG) {
                     Log.d(TAG, "onPostExecute - setting bitmap");
                 }
-                setImageBitmap(imageView, bitmap);
+                setImageDrawable(imageView, value);
             }
         }
 
         @Override
-        protected void onCancelled(Bitmap bitmap) {
+        protected void onCancelled(BitmapDrawable value) {
-            super.onCancelled(bitmap);
+            super.onCancelled(value);
             synchronized (mPauseWorkLock) {
                 mPauseWorkLock.notifyAll();
             }
@@ -349,18 +361,19 @@ public abstract class ImageWorker {
     }
 
     /**
-     * Called when the processing is complete and the final bitmap should be set on the ImageView.
+     * Called when the processing is complete and the final drawable should be 
+     * set on the ImageView.
      *
      * @param imageView
-     * @param bitmap
+     * @param drawable
      */
-    private void setImageBitmap(ImageView imageView, Bitmap bitmap) {
+    private void setImageDrawable(ImageView imageView, Drawable drawable) {
         if (mFadeInBitmap) {
-            // Transition drawable with a transparent drwabale and the final bitmap
+            // Transition drawable with a transparent drawable and the final drawable
             final TransitionDrawable td =
                     new TransitionDrawable(new Drawable[] {
                             new ColorDrawable(android.R.color.transparent),
-                            new BitmapDrawable(mResources, bitmap)
+                            drawable
                     });
             // Set background to loading bitmap
             imageView.setBackgroundDrawable(
@@ -369,7 +382,7 @@ public abstract class ImageWorker {
             imageView.setImageDrawable(td);
             td.startTransition(FADE_IN_TIME);
         } else {
-            imageView.setImageBitmap(bitmap);
+            imageView.setImageDrawable(drawable);
         }
     }
 

samples/training/bitmapfun/src/com/example/android/bitmapfun/util/RecyclingBitmapDrawable.java

@@ -0,0 +1,103 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.example.android.bitmapfun.util;
+
+import android.content.res.Resources;
+import android.graphics.Bitmap;
+import android.graphics.drawable.BitmapDrawable;
+import android.util.Log;
+
+import com.example.android.bitmapfun.BuildConfig;
+
+/**
+ * A BitmapDrawable that keeps track of whether it is being displayed or cached.
+ * When the drawable is no longer being displayed or cached,
+ * {@link Bitmap#recycle() recycle()} will be called on this drawable's bitmap.
+ */
+public class RecyclingBitmapDrawable extends BitmapDrawable {
+
+    static final String LOG_TAG = "CountingBitmapDrawable";
+
+    private int mCacheRefCount = 0;
+    private int mDisplayRefCount = 0;
+
+    private boolean mHasBeenDisplayed;
+
+    public RecyclingBitmapDrawable(Resources res, Bitmap bitmap) {
+        super(res, bitmap);
+    }
+
+    /**
+     * Notify the drawable that the displayed state has changed. Internally a
+     * count is kept so that the drawable knows when it is no longer being
+     * displayed.
+     *
+     * @param isDisplayed - Whether the drawable is being displayed or not
+     */
+    public void setIsDisplayed(boolean isDisplayed) {
+        synchronized (this) {
+            if (isDisplayed) {
+                mDisplayRefCount++;
+                mHasBeenDisplayed = true;
+            } else {
+                mDisplayRefCount--;
+            }
+        }
+
+        // Check to see if recycle() can be called
+        checkState();
+    }
+
+    /**
+     * Notify the drawable that the cache state has changed. Internally a count
+     * is kept so that the drawable knows when it is no longer being cached.
+     *
+     * @param isCached - Whether the drawable is being cached or not
+     */
+    public void setIsCached(boolean isCached) {
+        synchronized (this) {
+            if (isCached) {
+                mCacheRefCount++;
+            } else {
+                mCacheRefCount--;
+            }
+        }
+
+        // Check to see if recycle() can be called
+        checkState();
+    }
+
+    private synchronized void checkState() {
+        // If the drawable cache and display ref counts = 0, and this drawable
+        // has been displayed, then recycle
+        if (mCacheRefCount <= 0 && mDisplayRefCount <= 0 && mHasBeenDisplayed
+                && hasValidBitmap()) {
+            if (BuildConfig.DEBUG) {
+                Log.d(LOG_TAG, "No longer being used or cached so recycling. "
+                        + toString());
+            }
+
+            getBitmap().recycle();
+        }
+    }
+
+    private synchronized boolean hasValidBitmap() {
+        Bitmap bitmap = getBitmap();
+        return bitmap != null && !bitmap.isRecycled();
+    }
+
+}